ImBatch - ImBatch is a batch image processor with a nice graphical user interface.
Tweeig - Repost any tweet to Instagram or other social media
DVDVideoSoft Image Convert and Resize - Free Image Convert and Resize is a compact yet powerful program for batch mode image processing.
Twiger - Share tweets on Instagram
Ralpha Image Resizer - High-speed image batch conversion tool
TweetPik - Easily convert tweets to images SVG, PNG and JPG