What is the best alternative to Adobe Illustrator which allows for the same feature as Puppet Warp tool? Please suggest any simple tool which allow warping vector graphics. Preferably app for iPad or any online tool.
I can tell you I've two preferred vector graphics tools on iPad (Concepts App & Affinity Designer) and one I use far less frequently (Adobe Draw) and though they each have their areas of competency, none of them replicate the Illustrator Puppet warp that I am aware of, nor am I aware at this moment of tools specific to this use case.
There are a huge number of animation tools for iPad, but most are raster based AFAIK.
I do know you can open Affinity Designer files in Affinity Photo, which has envelope and mesh warp tools, so this might help, but I'm not sure your affected layers remain vector in that process - I rather think they get rasterised on the fly.
Hope this is of some help; good luck!