There is provided an information processing apparatus including a processor which executes a function of acquiring activity information indicating at least an activity of a subject, the activity information being inputted by an inputter, a function of generating support information supporting the activity of the subject on the basis of the activity information, and a function of controlling an output of the support information to the inputter or an observer who is different from the subject and the inputter on the basis of the support information or the activity information.
Please help me write a proper abstract based on the patent claims. CLAIM: 1. An information processing apparatus comprising a processor which executes: a function of acquiring activity information indicating at least an activity of a subject, the activity information being inputted by an inputter; a function of generating support information supporting the activity of the subject on the basis of the activity information; and a function of controlling an output of the support information to the inputter or an observer who is different from the subject and the inputter on the basis of the support information or the activity information. 2. The information processing apparatus according to claim 1, wherein the function of controlling the output of the support information outputs automatically the support information to the inputter or the observer according to content of the support information or the activity information. 3. The information processing apparatus according to claim 2, wherein the function of controlling the output of the support information outputs automatically the support information to the inputter or the observer in a case where the support information includes advice for the activity of the subject. 4. The information processing apparatus according to claim 3, wherein the function of generating the support information generates the support information including the advice for the activity of the subject on the basis of knowledge information regarding the activity of the subject. 5. The information processing apparatus according to claim 2, wherein the function of controlling the output of the support information outputs automatically the support information to the inputter or the observer in a case where the support information or the activity information indicates that the activity of the subject is statistically different from a normal activity. 6. The information processing apparatus according to claim 5, wherein the observer includes a plurality of users, and wherein the function of controlling the output of the support information determines one of the plurality of users to whom the support information is to be automatically outputted according to the content of the support information or the activity information. 7. The information processing apparatus according to claim 2, wherein the function of controlling the output of the support information outputs automatically the support information to the inputter or the observer in a case where the inputter or the observer is estimated to be unengaged on the basis of the activity information. 8. The information processing apparatus according to claim 7, wherein the function of acquiring the activity information acquires the activity information further indicating an activity of the inputter or the observer, and wherein the function of controlling the output of the support information estimates whether the inputter or the observer is unengaged on the basis of the activity information indicating the activity of the inputter or the observer. 9. The information processing apparatus according to claim 8, wherein the activity information indicating the activity of the inputter or the observer includes information acquired automatically by a sensor. 10. The information processing apparatus according to claim 2, wherein the function of generating the support information generates the support information in real time when the activity information is acquired, and wherein the function of controlling the output of the support information determines whether the support information is automatically outputted to the inputter or the observer in real time when the support information is generated. 11. The information processing apparatus according to claim 10, wherein the function of controlling the output of the support information accumulates the support information in order to output automatically the support information later to the inputter or the observer in a case where the function of controlling the output of the support information does not output automatically the support information to the inputter or the observer in real time. 12. The information processing apparatus according to claim 10, wherein the function of controlling the output of the support information accumulates the support information in order to provide the support information according to a reference operation made by the inputter or the observer in a case where the function of controlling the output of the support information does not output automatically the support information to the inputter or the observer in real time. 13. The information processing apparatus according to claim 10, wherein the function of controlling the output of the support information destroys the support information in a case where the function of controlling the output of the support information does not output automatically the support information to the inputter or the observer in real time. 14. The information processing apparatus according to claim 1, wherein the activity information is generated by communication between an NFC tag disposed on a tool used for the activity of the subject and an NFC reader provided in a terminal apparatus held or worn by the inputter. 15. The information processing apparatus according to claim 1, wherein the activity information is generated by reading of a two-dimensional code disposed on a tool used for the activity of the subject, the reading performed by a reader provided in a terminal apparatus held or worn by the inputter. 16. An information processing method performed by a processor of a computer, the information processing method comprising: acquiring activity information indicating at least an activity of a subject, the activity information being inputted by an inputter, generating support information supporting the activity of the subject on the basis of the activity information; and controlling an output of the support information to the inputter or an observer who is different from the subject and the inputter on the basis of the support information or the activity information. 17. A program for causing a processor of a computer to execute: a function of acquiring activity information indicating at least an activity of a subject, the activity information being inputted by an inputter; a function of generating support information supporting the activity of the subject on the basis of the activity information; and a function of controlling an output of the support information to the inputter or an observer who is different from the subject and the inputter on the basis of the support information or the activity information. 18. An information processing system comprising one or more information processing apparatuses which execute: a function of generating activity information indicating an activity of a subject according to an input operation made by an inputter, a function of generating support information supporting the activity of the subject on the basis of the activity information; a function of controlling an output of the support information to the inputter or an observer who is different from the subject and the inputter on the basis of the support information or the activity information; and a function of outputting the support information to the inputter or the observer.