I'm worry that WF been corrupted or tampered DURING the download
You are right, a file may potentially get corrupted during the download process, and to check the downloaded file's integrity its correct MD5 hashes had better be available.
In any case, there is a problem for public WinFlip hashes?
The archive WFlip0.50.zip is not large, and it is also possible to check its wholeness by testing the archive with an archivator. Nobody has seemed to care, and the MD5's have not been updated. But you're right that they should be updated with each new version.
The MD5's for WinFlip0.50 will be updated, it should be no problem.
Edit:
WinFlip Ver.0.50599 Kb
WFlip050.zip - tokyodownstairs.com
MD5:
A761F552D981AB829A7A4B5EA62912A4
599 Kb
WFlip050.zip - stylekings.de
MD5:
A761F552D981AB829A7A4B5EA62912A4
===========================
579 Kb
WFlip050.izh - stylekings.de
MD5:
885A766340A3B7071E9CF6441EF41021

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