Since i found no other options to control Hyperion with my iPhone to be that appealing, i just made a few Shortcuts. You can use them from the Shortcuts App, Homescreen, Siri (when it works 
) and with the Shortcuts Widget (Add the Widget, at least the 1x2 Size with 4 Shortcuts, then (Press and Hold), Edit Widget, Folder -> Hyperion, Order is as in the Shortcuts App)
For just the download skip to the bottom.
SETUP
You will obviously have to put in the internal / LAN Server IP Address of your Hyperion Device, if you are using a raspberry pi / most linux you can get it by running ip a in the console, windows ifconfig in Terminal, macOS ipconfig; or for almost all devices somewhere in the Settings there should be an "internal IP(v4)", something like 192.168.X.Y or 10.X.Y.Z, sometimes 172.16.X.Y
Adding the Shortcut should already prompt you to set up everything correctly with the full address you have to put in, but in case you messed it up here is the entire address again: http://[ip-address]:8090/json-rpc
I would strongly recommend to put all the Shortcuts into a Folder in the Shortcuts App, so you can use the Shortcuts Widget more easily or just have easier access.
If you want to add more features you can take this site: https://docs.hyperion-project.org/json/Control.html and look up the control you want, then look at the inner workings of some of my shortcuts to make your own.
MAKE YOUR OWN
Basically you have to add a Get Contents of URL Block, using Method POST with Request Body JSON. In that Body you always need the Text Field command (Key, left part of the field) and the command name in the right part of the field, i.e. color. Then you can look at the example commands or the Property Table on the Docs and add all other required fields. The Types are named somewhat differently, so here is a list:
String = Text
Integer = Number (Float also = Number)
Array = Array
Object = Dictionary
Boolean = BooleanIf the docs want an Object Type, you will have to add a dictionary, then click on the blue text 0 Items, and then add new fields in there again, using the names from above.
For example, if you want to add this command as a shortcut
{
"command":"adjustment",
"adjustment":{
"gammaRed":1.5
}
}Then you will need a Get Content of URL Block with a Text Field with the Key command (all with no quotes), then a dictionary with Key adjustment, with one field in the dictionary, being a number with Key gammaRed and a Value of 1.5
DOWNLOAD LINKS
Toggle Hyperion (Output On/Off): https://www.icloud.com/shortcu…26494460a99b28333ac3eeaba
Restart the Hyperion Server App/Process: https://www.icloud.com/shortcu…9ffff49239e9e43f5ff6ae4e8
Control Brightness (with a popup asking you to set it interactively): https://www.icloud.com/shortcu…278bf41a592621fceff425d3e
Set Mode to Idle: https://www.icloud.com/shortcu…99bdf4d5f879632a4bb90244a
Set an Effect interactively (The examples given in the prompt are not exhaustive, they are rather just to show the Naming Conventions): https://www.icloud.com/shortcu…dd4c44aada92f658046e34659
Set the Source to 250 (example, change it in the shortcut, if using my Effect Shortcut, that is also the Priority Channel of the Effect Added by the Shortcut. That way you can switch to and from it without having to re-input the Effect Name): https://www.icloud.com/shortcu…678ec45bebf87eeb79362b6fd
Switch to Screen Input Mode (If you have set it to be Priority 100, which is the default i think. Else, either change the Hyperion Settings or the Shortcut): https://www.icloud.com/shortcu…cd43e4058835140911c3eb556