下载并安装“Klammer”应用程序。 打开邮件应用程序（或其它包含你想打开的EML文件的应用程序）。 点击下载的文件。 点击“在Klammer中打开”。

Given the above summary, write a detailed text in English for it.
This app is available from the App Store, and costs $0.99. It will allow you to open and view the contents of an EML file. THis is currently the only way to view EML files without converting them first on another platform. You can use Klammer to open EML files that are attached to email messages, in your Dropbox or other cloud storage service, or in any other program that handles files.  If you're using Mail, you'll need to tap the attachment once to begin downloading it to your iPad. If you're using Dropbox or Google Drive, you'll need to download the file to your iPad. If the attachment doesn't download, try forwarding the message to yourself and downloading again. You will be prompted to select an app to open the file in. The EML file will be loaded in the Klammer app, and you'll be able to view it with proper formatting.