Rango Exchange Ideas

Is there anything out there already or can you guys write a program that say interfaces with crypto bubbles or similar that the user can enter a range of settings that allows the user to either enter the price they paid for that coin say XRP at $0.45c, your software then allows me to set the amount of coins I want to sell either an amount say 500 or your software knows how much I hold in my wallet and I can set it to sell 25% assuming I hold 2000 XRP, there could be a multiplication factor I want to sell it at say 10x so $4.50 and sell 500 XRP or if that is too difficult is it possible to have notifications for all the coins/memes I hold once the market reaches the set target sell price. I would happily pay for that software you could also make it a 12mths subscription and also limit the amount of coins/memes a user can monitor for the level I have subscribed too, say $49.99 to monitor up to 25 coins, $74.99 for up to 50 coins, $99.99 for up to 100 coins, $149.99 Thanks, Paul