Short answers to the questions we get most.
Everything, up to a point: the free version lets you build up to 10 floors, start three new towers, and reach a ★2 rating. That's enough to know whether the game is for you.
One purchase unlocks the whole game: unlimited height, every facility, all three building sites (city, sea, desert), and the full star ladder, all the way to ★5. It applies to the towers you've already started, too.
Exactly one: the unlock above. There are no consumables, no currencies, no subscriptions, no ads, and nothing time-limited. Buy it once and you own the game. The price is shown in the App Store in your local currency.
Not any time soon, honestly. The game is written in Swift against Apple's Metal graphics API, so a port would be a rewrite rather than a checkbox. Never say never, but iPad, Mac and iPhone are the home for now.
Since version 1.2 the same app runs on iPhone, including iPhone Duo. The controls fold into a compact layout (one row on top, a tab row at the bottom) and a status page with the clock, money, population and minimap is one tap away. It is the same game and the same purchase, but you spend a lot of time reading a whole floor at a glance, so iPad or Mac is still the better place to build. An unfolded iPhone Duo shows the full layout.
No account, no sign-in, and it plays fully offline. The only network involved is the App Store itself when you buy or update.
Not currently. Your tower is saved on the device you built it on. The game saves automatically as you play.
Twelve, including English and Japanese. It follows your system language.
It's not a remake, but the lineage is obvious and loved. The classic tower sims are the reason this game exists; the new part is that the building itself (its shape, facade, glass and neon) is yours to design, and every room's interior is generated live.
Yes. Yume Tower is on the App Store for iPad, Mac and iPhone.
Write to dev@yumetower.com. English or Japanese are both fine. It's a one-person studio, so replies come from the person who wrote the bug. The support page lists what helps in a bug report.
Yes, always, monetized or not, and you never need to ask first. The creators page is a standing permission you can link in your description. If you do make something, we'd love to hear about it.