SensorCraft adds modular sensors to the game. On their own they're just expensive decorations but filled with modules they emit a redstone signal based on these modules. You can, for example, count blocks, monsters or check if it is raining. There is also space for modifiers that let you block the redstone signal of a specific side or blacklist blocks when counting them.
1.9 versions require CXLibrary
There is also a mobile sensor that, except from emitting a redstone signal, does the same as the block one:
All the things (as of now):
The API can be found here
Modpacks:
You are allowed to include the mod in a modpack if you give visible credit to me (CubeX2).