Tweetlet - Tweetlet is a free tool that lets you create beautiful images from your tweets, text, and any other images in a snap.
RiteTag - No idea which hashtags to use? Get instant hashtag suggestions for images and texts on desktop and mobile.
Poet.so - Capture and share Twitter posts as beautiful images
Tagsdock - Tag Instagram photos instantly from your iOS keyboard.
Snap a Tweet - Snap a tweet with this little tweet screenshot tool.
Hashtag Suggestions for Instagram - Find the best hashtags for every photo