I had almost identical stats.
I tested my dev/demo site on various devices (computers/browsers) and connections and all loaded near instantly.
When loading the site on the AppMySite preview app, the site almost always takes 10+ seconds to load.
I found an alternative app builder and decided to give it a test and compare the stats. I disabled AppMySite WP plugin and installed/activated the alternative. I ran the alternative mobile preview app and it loaded within a split second.
So the comparison was night and day. I wonder if there’s something that needs to be done on AppMySite’s end, cacheing, pre-loaders, and/or other things to up the performance and help with load times. It’s hard to believe that a site scoring extremely high on GTMetrix is doing great on web browsers but is extremely sluggish on a mobile app.
Keep in mind, I understand the API requests is a factor and may contribute to load time differences between browser and mobile app but it’s hard to justify such a huge lag when two different mobile app builders have been compared with one taking 10+ seconds to load and another only takes a second.
I’m hoping that someone can reply to this and possible app-side optimizations can be considered to hopefully boost performance.
With all that being said, I think AppMySite is an amazing concept and has so much potential, the only issue for me right now is this sluggish load time for the mobile app.