Pushover - Real-time notifications on your Android, iPhone, iPad, and Desktop
Creative Market - Buy and sell handcrafted, mousemade design content like vector patterns, icons, photoshop brushes, fonts and more at Creative Market.
Pushbullet - Pushbullet - Your devices working better together
SocialSizes - Sketch templates for sharing images & videos on social media
Gotify - a simple self-hosted server for sending and receiving messages
Icons8 Developer API - 500k+ design assets, now available on-demand