Проверьте, пожалуйста, сочинение на английском (100 слов)

Даже если не брать во внимание ошибки, которые вы допустили, все сочинение совершенно неудобоваримо. По принципу - что вижу, то пою. В сочинении должна быть соблюдена определенная структура. Также не стоит переводить с русского; желательно находить эквивалент в английском. А для этого нужно больше читать, смотреть и слушать.
Что же касается непосредственно сочинения, то исходя из общего смысла вами написанного, я бы модифицировала его следующим образом (не все фразы и слова сохранены: надеюсь условием вашего задания не было употребление конкретных слов и выражений):

My treasured possession is my Sony Xperia ZR smartphone. There are several reasons for this.
First, it is the most useful gadget I have. I love the idea of an instrument that brings together various applications. Combining the best Sony technologies, my smartphone gives me seamless access to the hottest content, photos and movies, as well as allows me read the books, listen to music and surf on the web just with few clicks! Although it was first released in 2013, it is able to run the most recent apps and software just fine.
Second, the Xperia ZR is a smartphone that is dust-resistant and completely waterproof to depths of up to 1,5 meters for up to 30 minutes. It can take great photos and videos underwater so I am actually able to capture all those fun epic moments in a very sharp and crisp quality.
And finally, the smartphone’s sleek, yet durable design, really appeals to me. It feels solid and steady at hand. The backside of the device is made of soft-touch plastic that is warm and pleasant to the touch. Its alive, ‘young’ style is matched by classic black color.
I love my Sony Xperia ZR smartphone! It is one of the best phones in terms of features, performance and beautiful design.

I love the idea of an instrument that brings together a lot of different applications. I can read books, listen to music, surf the web just with a few clicks! It's fantastic, especially compared to the technological instruments of only ten years old.
I think that this one is the best smartphone in the world! This model is Sony Xperia ZR. It has advanced features and it is incredibly powerful. My smartphone is very light and it is quite enough. It is in sale since 2013. My smartphone colour is black. Its back cover is made of soft touch plastic. It is very pleasant to the touch the material. I like my smartphone!