Android - Where can find older versions of Apps?

Some alternative repositories, such as F-Droid, allow you to choose which version you want to download; all versions ever offered are in the repository.

For most other sites, including the Android Market, the latest version is all that is available.

The site Freeware Lovers collects freeware Android apps and has old versions for many of the apps they host. (Also for BlackBerry, Symbian, and Palm OS.)

The safe and correct way to get an older version is contacting the developer. Maybe they will just give it to you or maybe not - there is a reason why they updated it in the first place. Most importantly they will want to know why and you won't get any hacked malware version as is possible from other sources.