PAFCalc (Planted Aquarium Fertilizers Calculator) for Android is a useful utility that helps in calculations related to DIY fertilizers for planted aquariums. It has been completely written with the Android developer studio, which should ensure portability to tablets and smartphones. The app doesn't access any external functions on your device.
Gespeaker is a GTK+ frontend for espeak. It allows you to play a text in many languages with settings for voice, pitch, volume, and speed. The text can also be recorded to a WAV file for future listening. Gespeaker supports the speech synthesizer MBROLA for a better speech experience.
Hierarchical Cluster Engine is a a solution that can be used to construct custom network meshes or distributed network cluster structures with several types of relations between nodes. It supports handling of management requests from multiple source points, native reduction of results from multiple nodes (aggregation, duplicate elimination, sorting, etc.), a powerful full-text search engine and data storage, transaction-less and transactional request processing, and many language bindings for client-side integration.