This guide was written and first published on the Facebook fan page by Frumius; thanks for the permission to publish it here.
Early success on Radiation Island is a matter of figuring out which things to craft first. If you go to the crafting menu, you can tap on a given item there to see what materials you need to possess in order to make that item.
You're going to need some tools and supplies to survive. Some you will make (craft), some you will find, and some you'll take from enemies. You can't craft everything immediately; you'll have to craft some basic tools in order to get the materials to craft more advanced tools.
Let's say you are going to make the Iron Ax, because eventually you will. You'll need to have Wood (4), Iron (3) and String (2):
Wood - Chopped from trees (you need to make the Stone Ax first, see below).
Iron - Use the Furnace to smelt Iron Ore found in iron rocks that you mine with a Pick, which requires 2 Flint and 2 Wood. To make the Furnace you'll need Stone, Flint and another material. The Furnace is great for cooking meat to make it go MUCH farther, for smelting ore and making Glass from Sand. The Furnace also produces Charcoal as a byproduct of burning wood. You can then use Charcoal as fuel to smelt and cook, and later you can use it as an ingredient of ammo.
String - Made from Fiber from the bushes and large plants (plants between grass size and tree size). To harvest Fiber, hit the bushes with your bare hands (using the attack button), or with a Machete or other blade that you make or find. You can also find Fiber as an item that zombies drop after they've been killed.
Here's how to go about Crafting it - To harvest the wood that you'll need for the Iron Ax, you'll need to use a Stone Ax on a tree. Tap on the Stone Ax in the Crafting Menu to see what it takes to make that -- not much; I think only some twigs and some flint. You can find Twigs and Flint lying on the ground, and you can also get Twigs from hitting trees with your bare hands. You can use your bare hands to get Twigs from trees and Fiber from big plants.
How do I use my bare hands if I'm already holding something? In the quick slots or in the backpack, tap on the item you're carrying in order to free your hands of it.
You see that there is a progression of things that you need to do or make as you advance in your tool technology. Some things you may not end up making because you either found them or found some other way to do things; I never made a bow, I found it in a crate over at the cement ruins by the first cabin.
The wolves that are getting you now will be easier to handle with an Iron Ax, easier still with a Titanium weapon, and best of all with a ranged weapon like the Boomerang, a Bow or a gun. The Iron Ax can also be used to mine ore.
Once you get to a certain level of advancement, you tend to find more loot and need to craft less, because you're going into strongholds, pillaging the crates you find there, and taking from the bodies of the undead you've slain. You end up making ammo from time to time. You find a lot of food -- Fish and Raw Meat that you can cook in your Furnace to make meats go about 3-4 times as far.
How do figure out how to craft anything? Say you want to cook your meats. To cook, you must build the Furnace. To find out how, open your Crafting Menu and find the Furnace. Tap on the Furnace, and it will show you what you need to collect in order to make it. Tap on any item you see in the crafting menu to find out how to make that item.
Not only does the Furnace cook meats, but it also creates refined Iron and Lead from iron and lead ore, and Glass from Sand. Using Wood or Twigs in the Furnace creates Coal as a byproduct (very handy). You can use Coal to make ammunition, and as a source of fuel for the Furnace. To use it, put your meat or ore in the top-left compartment of the Furnace, and put your fuel in the top-right compartment. Coal, Wood, or Twigs can be used as fuel. Coal is best. The bottom two slots are where your finished products come out.
I like to upgrade my Backpack as soon as possible so I can carry more stuff. Upgrading the Backpack requires Leather hides and Rope. You get hides from killing wolves and lions; these hides are different from Wool you get from sheep or Bear Skins from bears and Crocodile Skins from crocs. You can upgrade the Backpack five times, each time gaining another row of six storage slots to hold your items.
When should I leave the beach?
That's a question we each must face! I didn't want to move out until I had medicine, bandages, splint, bow, arrows, cooked meat (it goes 3-4 times farther) ... in other words, you just have to make a break for it when you think you're ready.
Cooked meat goes 3-4 times farther -- especially Fish. Build the Furnace (as mentioned above) to cook meat. When you cook a piece of meat, it produces two hamburger patties. Hamburger patties fill your stomach much more than raw meat. And since you get TWO patties for a single piece of meat, it's a significant gain in efficiency. Fish yields three patties! So definitely cook your meats.
Visit the Houses marked on the Map
The houses marked on the map are the ones to use as bases while you explore, because they have have beds that allow you to sleep through the night, and which then act as new spawn points. Note that you first have to visit them in order for them to become transit/spawn locations.
"X" Marks on the Map
The "X" marks on the map are sites with buried chests. Craft a shovel to dig at those sites and discover useful random items (e.g., clothing, food, ammo, tools, guns, medicine, etc.).
Build storage boxes out of wood to store things that you don't have room to carry. Build them at houses or Transit stations, which you can use as bases.
Transit Locations are special houses you discover along the way that allow you to "fast travel" to them at any time (unless an enemy is threatening you). Use them by accessing your map, tap the map to zoom in, and then tap a Transit location. When you discover them, transit locations become marked on the map by the icons looking like an old ship's steering wheel (or compass).