Comic Books Collector by Sweet Lime Solutions is a mobile app that will keep track of the comics you own or want. It can be downloaded off of the Google Play store, it is a little over 500k in size and needs Android 2.2 or higher installed on your handheld device. Below are some of the pros and cons I found with the app.
PROS: The database is quite extensive for comic titles because it uses the Comic Vine API. The app is easy to learn and use. You can select whether you own the digital or print version of the title you have (so you can have a list of the digital titles you have as well as the physical copies). You can export your list to an excel file to view on your computer. You can also share the titles in your collection on Facebook or Twitter.
CONS: You cannot pick which cover to display on the app if the issue has variants, so the cover you see may not necessarily be the in your collection. You cannot put in more than one copy of the issue, for example if you own multiple copies of the comic or both the digital and print version you can’t change the quantity on the app for your own records.
So far my overall experience with the app (I have been using the free version) has been good. Despite the cons I listed above, which I hope are fixed in an upcoming update, I am thinking of upgrading to the Variant Edition (a copy of the app with a few more features for $3) of the app. Below are some screenshots from the app to show you how it looks.