Way back in 2007 BerryLogic released two commercial applications, Add To Calendar and BBChecklist, and then removed them from the market. The apps were pretty popular and I know many people who purchased Add To Calendar.
Tashanna let me know that the developer recently posted on BBForums that he has recompiled both Add To Calendar and BBChecklist as free applications which is pretty generous. He does says that:
I won’t really have time to handle support requests for this, so they are pretty much as-is. I know they worked on Pearl and Curve, but I have no idea about any of the newer versions.
So if you were looking for copies of the apps you can now find them at www.bbsoftware.info for both OTA and desktop installation. Let us know if they work for you and with newer OS builds! I tried BBChecklist on my 9700 and it worked like a charm though it was not as refined as some other options.