In our regular IAP Inspector column, we examine monetisation in free-to-play games from the players' perspective.
This means looking at the various pressures to spend money, as well as the value offered by in-app purchases and weighing up whether or not it amounts to an enjoyable experience.
In 2016, as in any other year, we've seen a healthy mix of different monetisation techniques and balances and have used our full ranking system - Approved, Passed and Rejected.
But with 2016 now drawing to a close, we've rounded up the games that stick in the mind as the best examples of thoughtful and player-friendly monetisation we've encountered throughout the year.
If you missed any of these when they came out, now would be a great time to go back and see why we hold them in such high regard.
But after slating Glu Mobile's Frontline Commando: WW2back in 2015, one can imagine our surprise that Rival Fire - itself a Frontline Commando title until just before launch - should look so different.
We observed "one simple, fundamental difference between Frontline Commando and Rival Fire: the former rations and controls its players' session lengths, while the latter encourages players to play for as long as possible".
But as well as lacking a restrictive energy system, we also praised Rival Fire for doling out hard currency with surprising readiness.
Perhaps best, though, was all the things you could do with it.
Rival Fire's gacha system
"The entire game economy is now much more sophisticated, granular and deep," we wrote.
"You can level up entire guns. You can level up different gun components. You can level up your armour and various armour components. You can also level up your squadmates. And buy new ones."
Of course, the root of Rival Fire's deep, Asian-style monetisation is that the game is a culturalisation of Tencent's WeFire.
But UK studio Eight Pixels Square - recently acquired by Outplay Entertainment - managed to inject a little of the same flavour into base-builder/shoot-'em-up hybrid RAID HQ from its studio in Derby.
We particularly praised the VIP system here, which provides rewards for paying players that remain with them for their entire time with the game.
"For instance, a purchase of 500 Gems permanently upgrades the three-hourly Free Chest to a VIP Chest, offering a better chance of getting Rare cards," we wrote.
"It also gives you a 10% resource boost on all raids by default (non-payers have to watch an ad) and gives you a VIP icon for all to see."
Video ads are also implemented in a way that's rarely seen in the base-building genre, allowing the player to knock ten minutes off a long wait timer by watching one.
Good retailing offers round off a nuanced and ultimately player-friendly example of free-to-play monetisation.
Clash Royale's genius lies in its chests. Back in March when the game launched, we wrote that "this one mechanic effectively [ties] together three free-to-play systems".
"The first is the aforementioned wait timer, which costs hard currency to bypass and is the main way you'll be spending Gems in Clash Royale," we said.
"Secondly, there's the gacha element - the fact that each chest contains a random selection cards and Gold - that satisfies the F2P player's well-documented love for random rewards, thus making them more compelling.
"And finally, there being only a limited number of chest slots results in a situation that's tantamount, in practise, to a classic free-to-play energy system.
"[...] But the fact that it's simply the threat of losing out on rewards, rather than a hard gate, seems to me a far more thoughtful approach to the system - and one that should be taken up by others."
And with Clash Royale marking yet another runaway success for Supercell, it no doubt will be.
We called FIFA Mobile the game to finally nail free-to-play football, and it's all down to one idea.
Called Attack Mode, this asynchronous multiplayer component cuts out everything but the goalmouth action across a game of two halves (each).
"But while many other developers have made great mobile games that are only let down by their lack of effective free-to-play monetisation, FIFA's issue has been the opposite," we wrote.
Finding the balance
And indeed, FIFA has long been enjoying the spoils of Ultimate Team as a secondary revenue stream on the console versions, and the last few entries have brought the formula to mobile.
It's the same here. Real money can be paid for FIFA Points or premium player packs, while it's equally possible to play for free by scraping together coins and taking to the transfer market.
But with the addition of Attack Mode, this is the first time FIFA has felt like a truly modern free-to-play mobile game.
FIFA Mobile's Attack Mode
"FIFA Mobile is not just the first entry that shows any signs of truly understanding the platform, but it's also the blueprint for what I believe will be FIFA's free-to-play future," the IAP Inspector's original piece concluded.
But the US arm of the Japanese developer impressed us with this city builder back in January.
In a way that's particular to Japanese games, Downtown Showdown loves to shower the player with free currency and other rewards.
Gifts galore
"Carrying over the liberal approach to hard currency established in Rune Story, you're awarded 100 ($0.99) every time you level up," we wrote.
"There's a respectable dripfeed along the way as quest rewards, too."
This means that a reward is never far away, and that hard currency Diamonds are in plentiful supply.
Add in a VIP system that offers rewards of actual value - an increasing number of free pickaxes and chainsaws every day, worth $0.50 apiece - and spending proves itself good value, too.
Maybe it's not a formula for success in the West, but it certainly makes for an enjoyable player experience.
Matt is really bad at playing games, but hopefully a little better at writing about them. He's Features Editor for PocketGamer.biz, and has also written for lesser publications such as IGN, VICE, and Paste Magazine.
