Having to block unwanted calls is unpleasant enough. nope makes the process simple and painless with state-of-the-art design and reliable blocking of calls, texts, and text spam. With nope., you control when your phone rings.
IMPORTANT! Please do not update to 4.4 KitKat yet as you will lose SMS Blocking capabilities
Please star this feature request so that Google can allow 3rd party apps to do what they do best!
https://code.google.com/p/android/issues/detail?id=61684

Features:
- 100% FREE! If you'd like to donate to the developer, there is a donate button in the app!
- Block unwanted calls, texts, or text spam (*Text blocking capabilities disabled in 4.4*)
- Blocked Calls Don't Ring! You choose what to do with blocked calls:
-- Pickup and Hangup / Disconnect.
-- Send to voicemail.
-- Mute ringer.
- Personal call blacklist/whitelist
- Personal text blacklist/whitelist
- Smart text spam blocker automatically filters text bombs
- Option to automatically block unknown/private numbers
- Export your block logs to a .csv file!
- "Out of Office Mode" lets you block all incoming calls or texts (except for the numbers on your whitelist) for a specified amount of time. If you want complete silence, you can include your whitelist in this mode as well!

How is nope. different than all of those other "Call Blocking" apps?
When you install nope., you instantly have a simple, easy to use way to block unwanted phone communications. Similar apps usually do one thing -- either call blocking, text blocking, or spam blocking. nope. packs all three into one simple, beautiful package -- all while following android's design guidelines. On top of that, nope. is free, and open source!

The goal of nope. was to create a comprehensive blocking application that was well designed, simple, and easy to use -- with features that worked. We hope you like it.

The source code of nope. is available on github here: https://github.com/justinharrison/nope.
To report a bug, create an issue on github.

Recent changes:
2.1.1:
- Fixed bug where nope. would not start on phone boot in some cases.
Bug was reported here. Thanks to user sneakernets for reporting this issue!
https://github.com/justinharrison/nope./issues/66