The ornamental design for a full-screen smartphone, as shown and described.
FIG. 1 is a top front perspective view of a full-screen smartphone showing my new design;
FIG. 2 is a bottom rear perspective view of the full-screen smartphone of FIG. 1;
FIG. 3 is a front elevation view of the full-screen smartphone of FIG. 1;
FIG. 4 is a rear elevation view of the full-screen smartphone of FIG. 1;
FIG. 5 is a left side elevation view of the full-screen smartphone of FIG. 1;
FIG. 6 is a right side elevation view of the full-screen smartphone of FIG. 1;
FIG. 7 is a top plan view of the full-screen smartphone of FIG. 1; and,
FIG. 8 is a bottom plan view of the full-screen smartphone of FIG. 1.
The broken lines immediately adjacent the claim represent the bounds of the claimed design while all other broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.