On his blog Innesential Brent Simmons makes some good points regarding the today’s announcement by Dropbox that it is returning some applications.
I’ll add that when deciding to use an application, you need to ask a few questions:
If the application is free, who is the real customer (probably not you)? For instance, Safari is core to Apple’s business because it makes Macs saleable, but Mailbox is not core to Dropbox.
How do the economics of the application work? Is the developer charging enough money to sustain themselves and have sufficient resources to improve the product over time?
How hard is it to transition your data to an alternative application should the one you are using be withdrawn?
Does the developer have a history you can look at (Omni: yes, Bare Bones Software: yes, Apple: yes, Google: yes). A developer’s past actions give good clues to what they may do in the future (e.g. Apple & Google have pulled beloved apps many times).