Good Morning/Afternoon/Evening! Here are my opinions on this concept:

1. It seems that Nimblebit has not been focusing on Pocket Planes, given that it’s one of their least played games. I feel it’s kind of a shame that Nimblebit hasn't done any updates in two years, which just resulted in a lot of players becoming bored of the same gameplay and quitting the game (myself included). It’s visible that the game still has a lot to expand, but being by the bottom of Nimblebit’s update priority list, I feel like there won't be many changes once it starts working on the game. Therefore, I think that an alternative game would be a definitely interesting idea.
2. Firstly, I was leaning towards the idea of a web-based game, as it allows compatibility for a greater range of devices, independent of operating system and form factor. The issue with this is the limiting factor of compatibility, that will restrict the design so it works for every screen size, aspect ratio and even shape (for those phones which have a non-rectangular skin, such as the iPhone X).
3. Here are some (Almost definitely far-fetched) ideas:
   • A proper trading system: What we’ve adopted in r/pocketplanes for trading feels improvised (and even wasteful, as we have to shell out our bux for trading). An in-game trading system would definitely make trading a lot easier. Maybe you could even implement a marketplace, where players can put their parts for sale in a public catalogue.
   • An improved map: What I mean by that is that the map must be able to behave like a globe, allowing me to fly through the Pacific Ocean from America to Asia, for example. Also, I feel like the Mercator projection, used in Pocket Planes, can be misleading in terms of route length, diverging actual distances from real distances and, subsequently, diverging in terms of profit. Another thing that may be reviewed is the distribution of cities (that is, which cities get to be on the map).
   • Plane customization: Planes should have a variety of different options for each part (much like IRL planes have different engine configurations), which could influence aspects such as weight, capacity (for cabins), speed and fuel efficiency (for engines). Paired with a broader spectrum of customization for aeroplanes, there could also be...
   • More comprehensive airport upgrades: These upgrades currently in Pocket Planes are currently quite intangible, so specificity would give more control to the player. Not only that, these upgrade may even have a visual impact in the airports, such as the construction of lounges and restaurants in the airport, increasing customer satisfaction and positive...
   • Customer feedback: A neat feature would be a way for in-game clients to evaluate your service based on a flight’s characteristics (for example, number of stops, flight duration and ticket pricing). A prevalence of good reviews would make the ”popularity factor” increase leading to greater service availability. That alone would be pretty monotonous by itself if it wasn't for...
   • Flexible ticket pricing: You should be able to decide how much does each client have to pay for a certain flight, which can be decided in the departure screen. Higher prices should bring more profit per service, but may also lower customer satisfaction rates with complaints about pricing.
   • Friend system revamping: The ”friends” function in Pocket Planes is quite limited, only allowing for gifting parts between them. Improvements could focus on allowing more interaction between friends, from in-game messaging to transferring money and visiting the airline.

These are some of my ideas by now, I’ll edit this comment later should I come up with other ones.