iTheme is described as 'Customize your iOS device's home and lock screen with great looking, editable themes. Change colors, add frames and special effects, calendars and other overlays'. There are seven alternatives to iTheme for iPhone and iPad. The best alternative is Winterboard, which is free. Other great apps like iTheme are Lockinfo (Paid), Pimp Your Screen (Paid), Dreamboard (Free) and Widgetize (Freemium).
Give your iPhone or iPod Touch a graphical overhaul! WinterBoard allows you to customize the appearance of your jailbroken iOS device and install third party themes. You can only get Winterboard from Cydia (on jailbroken iOS devices).
You can find this app in Cydia - Tweaks. You can setup your Lockscreen, Homescreen or both with weather, calendar, news, clock, date, message, missed cals,.... It is free for trial 14 days. Costs aprox. 7 USD.
Widgetize allows you to create custom photo widgets, date widgets, text art widgets, countdown widgets - and so much more with the new iOS 14 widget experience. It’s time for home screen design, with photos, text and shapes - or simply showing the time.
Add quick doodles, sketches, or scribbles to your home screen with Scribblet! Jot down a note, practice your hand-lettering, create your own home screen comic, doodle over an image, or maybe just draw that cool "S" we all mastered in middle school.