Backups are NOT the answer! If you are doing any kind of coding, you should use a revision control system, like SubVersion, GIT, or Mercurial. It will save SOOOOOO much heartache and pain.
Even for small personal projects, an RCS is essential. Full-featured IDEs (MS Visual Studio, NetBeans, etc.) have RCS interfaces built in. I could understand why Erel doesn't want the significant effort in supporting different RCSs in B4A, but even a standalone solution only takes seconds to commit or rollback changes.