1. add support of always available books
2. add popup menu
3. improve robustness in handling invalid text file of book pages
4. minimize permissions requirement

1. Embed text to the produced PDF file.

1. Bug fix and improvement of range download function.

1. Add leaf range selection support.
2.On range download, the range number was appended to the default downloaded filename.

1.Add hathitrust.org support.
2.Add PNG leaf type support.
3.Add Http 502/504 gateway errors support, when that happened download will retry, not just abort.
4.If the download button does not appear due to slow network, you can show it manually by pressing the extension icon on browser toolbar after the page being loaded.

1. Possible download succeeded with 0 byte PDF file for large books. Now fixed.
2. Version 115+ required.
3. No response when pressing the 'Download' button after a saveas dialog is canceled. Now fixed.
4. The function of download as image file does not work. Now fixed.
5. Pressing the 'Download' button to cancel a download process which has lasted for more than 30 seconds will leave with uncompleted files not cleaned. Now fixed.

1. Quality code is appended to the default downloaded filename.
2. The book will be returned automatically on successful download for availability to other users.
3. If "Always ask you where to save files" in "about:preferences" was checked, download may fail. Now fixed.

1. Possible leaf lost caused by unexpected abort. Now fixed.
2. Pressing the 'Download' button to cancel a download which has lasted for more than 30 seconds will leave with uncompleted files not cleaned. Now fixed.
3. Under incorrect settings, download succeeded but no PDF file found. Now fixed.

1. Downloads will now retry automatically on network errors. So it will work more smoothly than ever.
2. Download process can be aborted at any time. There is no need to wait for cleaning up any more.
3. Inaccurate button title place. Now fixed.

add support of version 114 and later.

Only version 113.0 supported.