https://airtable.com This is like Excel or Google Sheets, but it can do so much more. Because you can add images, recordings and tags to fields, it’s a great tool for collating data on virtually any topic. There are even customisable views to suit your data.
https://realtimeboard.com This tool is great if you want to collaborate on sketching ideas of early design concepts with distributed teams, as you can quickly upload your sketches with the app for discussion and voting.
InVision and Marvel
https://www.invisionapp.com https://marvelapp.com These tools are essential to test your solution on end users. You import your designs and place clickable hotspots over the top, which you use to link up pages, or change states on hover.
https://origami.design When you need to test any micro interactions in your UI, using Origami can help you prototype something quickly. Assets from your Sketch file can be pasted straight into the app and then you use a combination of patches to create interactions and smooth physics-based animations. Think of it as ‘visual programming’.