He/she's not a native speaker, might not have access to a native speaker for proofreading and a spell checker wouldn't pick up frontier vs barrier.
"it is not provide to provide free updates forever" doesn't make sense in any language.
The TL;DR is the first thing you see on the page. They author didn't proofread the first paragraph.
* TL;DR
each manual update review by Apple causes delay and drama
AppStore does not support paid upgrades, only new App, in-App purchase or subscriptions
Apple takes 30% and that is not sustainable to run a company and pay salleries
it is not provide to provide free updates forever
if you purchased our application this year we provide a direct license, if you had it
significantly longer, we think a paid upgrade is fair for continuously developing, improvements, and support
He/she's not a native speaker, might not have access to a native speaker for proofreading and a spell checker wouldn't pick up frontier vs barrier.