I've been using PostBuilder (used to be called gramspacer) for several months now and I use it almost every single work day. PostBuilder makes it super convenient for organizing and planning content for my Instagram pages and the founder is very responsive if you have questions or if there's ever an issue. I definitely recommend them!
Instaspacer - Putting the spaces back into Instagram
AllTheFreeStock - All the free stock images, videos and icons in one location
PicMerger - Merge photos side by side, create beautiful photo collages, customize your content with built-in photo editing tools, and more
CaptionBot by Microsoft - Analyzing and describing images by a bot
StoriesStudio App - StoriesStudio allows you to take a long video and cut it down into separate clips that can then be uploaded to Instagram stories, WhatsApp, TikTok, and more.
CloudSight - Image recognition API; send an HTTP request with an image, get a description of contents.