I've been using the iPhone/iPad app Wunderlist off and on for a few years to track my to-do list. I have a long list of things that need to be done, sometime, and as the years go by the list gets longer. I like Wunderlist.
I'm a bit late to the party, but found out today that Wunderlist were bought by Microsoft earlier this year.
I always have mixed feelings when apps I like are bought by bigger companies. On one hand, they might have more stability to keep going. On the other hand, they might get shut down, or changed to the point where they aren't useful to me.
I remember when Microsoft bought Skype. Well, Skype is still running, and it's the same as before, except the app has evolved to the point where I don't know how to use it any more. I hope Wunderlist keeps their design independence.