@Mirefox I also can't think of a timer, if you're sure there is one then perhaps you are thinking of a different game?
I confess that I'm so sad to see the demise of mobile premium titles that I actually purchase premium apps of interest even when I don't (yet) know when I'll get around to them, just to support the developers releasing premium options (Old Man's Journey being the latest, which I'm pleased to see just announced at Apple's WWDC that it won a 2017 Apple Design Award , I'll have to try harder to fire it up and play it).
As for Gems of War, I agree that at the level that I enjoy it the FTP model is very generous ... so much so that I applaud the developers for successfully navigating the treacherous waters of allowing the "whales" to spend as much as they would like to fund the active development of the game for those of us who are more casual.
That may be the secret to my enjoyment, while I would love to be a completionist and own everything completely maxed out, it's just not ever going to happen for me so I'm content to casually enjoy the journey. For me, I've got my difficulty setting on "Warlord I", which is the third of six possible settings for "Quests, Challenges, Casual PvP, and Arenas". That seems to be the sweet spot for my current roster since I prefer to casually use a "farm" team to gather souls while doing the non-competitive options.
I can appreciate that the frustration/stress of encountering opponents that are just too tough might be a drawback to some for enjoyment of the new Guild Wars, but for me it's offset by the challenge of trying to construct a color themed deck while dancing the tightrope of how far to go by limiting yourself. Fortunately for me, I also enjoy the cooperative aspect of Guild Wars, our guild roster is large enough that when I fail it's not as if my loss is the cause of our losing the war, and the rewards are modest enough that it's not a catastrophe if the guild doesn't prevail and we find ourselves adjusted to a different bracket of the matchmaker.
In fact, I comfort myself that it is the goal of the matchmaker to pit us against foes that we can't always beat, no matter how much money people spend the "whales" will see themselves battling it out amongst themselves at a difficulty level that I'll not see, but it's still essentially the same game for me that it is for them.
This is great advice and probably one of the keys to enjoying the game without feeling the need to spend money, outside of the desire to reward the devs and support development.